1. Field of the Invention
The invention relates generally to a rolling bearing, and more specifically to a large-size rolling bearing by which, for example, a main shaft of a wind power generation system is rotatably supported.
2. Description of Related Art
There is a conventional cage used in a large-size rolling bearing, and assembled in an annular shape by connecting together a plurality of split pieces arranged along the circumferential direction. For example, Japanese Patent Application Publication 2003-120680 (JP 2003-120680 A) describes a cage of a rolling bearing, which is formed of strip-shaped split pieces that hold rolling elements. A convex connection portion is formed at one longitudinal end of each split piece so as to project from the one end. In addition, a concave connection portion, which is shaped so as to conform to the convex connection portion, is formed at the other longitudinal end of each split piece. The cage is formed by arranging the strip-shaped split pieces along the circumferential direction and engaging the convex portions of the split pieces with the concave portions thereof. Note that, in the following description, “split piece” will be referred to as “cage segment”.
As described above, JP 2003-120680 A describes the configuration that allows the multiple strip-shaped cage segments to be engaged with each other along the circumferential direction. However, in the cage described in JP 2003-120680 A, because the concave connection portions extend through the cage segments in the radial direction, it is not possible to effectively prevent junctions of the cage segments from being displaced inward and outward in the radial direction. Therefore, when the cage segments are arranged in a circular pattern along the outer peripheral face of an inner ring, the cage segments may be easily detached from the inner ring. Further, when the rolling elements are fitted in pockets in a state where the cage segments are arranged in a circular pattern, the cage segments may be easily detached from the inner ring together with the rolling elements. Therefore, works of arranging the cage segments in a circular pattern and fitting the rolling elements in the pockets are difficult. As a result, a large number of man-hours are required to assemble the rolling bearing.